He dreamed of buildings and people interacting as a "highly evolved being."

The sun would warm them and the breeze would cool them. Nature would surround them.

The buildings would soar, reaching toward the sky with small apartments and large public spaces.

Soleri preached community and conservation. He wanted to save the planet and, in his way, save humanity. A culture of "hyperconsumerism," he said, could not be sustained.

He would build Arcosanti as remedy. It would be his experiment of thousands of people living together to teach the world how to grow.

Soleri was hailed as a futurist. In 1976, Newsweek magazine exclaimed, "As urban architecture, Arcosanti is probably the most important experiment undertaken in our lifetime."

Today, Arcosanti is a sliver of Soleri's original vision.

Some circular concrete structures dot the hillside, echoing the dramatic shapes of his early drawings.

It survives on a small stream of visitors. Architecture students pay to study with Soleri. Tourists pass through the gift shop to buy the bells and wind chimes he designed. Then they go home.

The place, at the end of a long dirt road, is home to about 80 people.

Paolo Soleri, the futurist, is 91 now, and Arcosanti remains more dream than reality. That might be why it still matters.

. . .

Sitting in his part-time home in Arcosanti, Soleri is surrounded by his drawings and sketches. The apartment is modest; the walls are raw concrete. But the sun fills it, and the view is spectacular. There is a drafting table on one side of the room and a single bed on the other. A book from a friend he met while making Leonardo DiCaprio's documentary about the environmental crisis, "The 11th Hour," sits on a table.

For decades, Soleri has written and taught about buildings and human nature. He speaks of places warmed by greenhouses where people convene to think and play.

Does he consider himself an architect or a philosopher?

"Oh, such big names," he says. "I am an earthling."

. . . Paolo Soleri was born in Italy in 1919. He earned a Ph.D. in architecture in 1946.

In 1947, at the age of 28, he came to America to learn from Frank Lloyd Wright at Taliesin West in Scottsdale.

The two architects could not have been more different. Wright's buildings sprawl. Soleri's ascend. Wright's homes work best in suburbs. Soleri was already beginning to imagine compact cities where cars would be unnecessary and people would live, literally, right on top of each other. There would be no suburbs.

Soleri married his wife, Colly, the daughter of a client, and in 1950, he moved back to Italy to design a ceramics factory. Six years later, he returned to Scottsdale and spent the next decade designing and building homes and bridges, among other things.

He began to dream of, and draw, large urban centers.

In 1961, his plans for a city of 2 million people were included in the Museum of Modern Art's exhibition "Visionary Architecture."

He later earned a Guggenheim grant to work on a project that became a book, "Arcology: The City in the Image of Man," published in 1969.

In it, he called for a "highly integrated and compact three-dimensional urban form that is the opposite of urban sprawl with its inherently wasteful consumption of land, energy and time tending to isolate people from each other and the community."

People would live, work and play in such well-designed areas, cars would be rarely needed. There would be privacy and community.

But Soleri was not just a dreamer. He knew his designs would work, and he knew the timing was right. With its radical reconstruction of the way people would live, Arcosanti captured the zeitgeist of the radical late '60s.

In 1969, he bought land 70 miles north of Phoenix and set about making his utopian city, his urban ideal, a reality.

The plans looked a bit like something the world would see later - a structure out of "Star Wars."

. . .

One afternoon a week, there is a session at Arcosanti called "School of Thought."

A group gathers in a classroom to learn about a Soleri concept.

The students are longtime residents and short-term guests, architects and admirers who visit to learn from Soleri.

At an August session, the topic is "The Quest for Coherence, Materialism, Consumerism and Hyperconsumerism." More than 30 people are waiting for Soleri as he enters the room with a cane.

His pants are pulled high. He carries his shirt draped over his arm and wears a white, sleeveless undershirt.

An Arcosanti employee puts a microphone headset on Soleri. Students ask questions into a microphone that transmits to the earpiece.

A student asks, should the residents do what is right for society or what is right for Arcosanti?

Soleri speaks slowly. "I don't make a distinction."

. . .

Today, Arcosanti is 3 to 4 percent complete. This summer, 82 people call it home.

Nearly everything is made of concrete. Soleri uses the material because it is affordable and durable and formable. But it does give the place a grayness.

There are 14 primary buildings - including some housing units, a foundry, a music center and a drafting-studio complex - and a swimming pool.

On an August afternoon, workers are scattered about. It is quiet, not bustling.

A man who has lived here for five months is cleaning the rooms that house the paying guests.

A group of young people are digging garden trenches for greenhouses, the next big project.

They are workshop participants, architecture students from around the world. A five-week stay costs $1,350, which pays for tuition, meals and housing.

They work in construction, facilities maintenance, agriculture, archives or landscaping.

It is hard work, and it starts early, but they are happy to get their hands dirty with practical work after years of studying architecture in classrooms.

The gift shop is where visitors can buy the famed Arcosanti bells that are made at the foundry. Soleri first started experimenting with them while building the ceramics factory in Italy.

Today, workers create them in ceramics and cast them in bronze using forms created with silt from the riverbed. Some bells sell for $29; one-of-a-kind bells signed by Soleri can cost $6,000.

Although the bells have nothing to do with Soleri's vision, their sales provide more than half of the money needed to keep Arcosanti running.

Every weekday morning at 11:45, there is an informal meeting for all residents at an open-air amphitheater named "The Vaults."

The concrete structure was the first built at Arcosanti, in 1971. It provides shade and captures a cooling breeze.

There are announcements about people visiting. A resident says she is going to Mayer, home of the closest major grocery store, that afternoon and offers a ride to anyone. There is a reminder about a seminar that afternoon. Somebody has lost her sunglasses.

. . .

During lunch in the cafe, Soleri sits alone at a table. The younger residents and workshoppers keep their distance. They seem intimidated. Eventually, some of the longer-term residents join him.

After lunch, Soleri says the progress is slower than he anticipated 40 years ago. "I would have been crazy if I thought it would be this slow. But of course, I stay. I don't have any choice. I am a prisoner of my own age."

He sees the world around him changing.

After decades of pushing to change the way the world lives, Soleri hears people talking about eco-friendly products. Green building. Hybrid cars.

Is that gratifying?

"Not true. I was working against the grain of the American dream, and I still am," he says.

Even when we talk about being green, we are still buying things. Even when we're making hybrid cars, we're still driving cars.

"We think we are now making the right decisions, but we are not," Soleri says. "That might be worse. We have so much to let go of."

. . .

The significance of Arcosanti is a matter of debate in the architecture community.

Michael Graves, a retired professor of architecture at Princeton University, says Soleri's work is more interesting than important.

"He took a position of living in his very special dream," Graves said. But Arcosanti was too remote, he said, literally and figuratively.

Was Soleri ever influential?

"No, to nobody," Graves said. "He was never able to mainstream anything, and you have to be, to be influential. People have to see it."

But there is another opinion, held by the architects who say Soleri's work changed them and they, in turn, influenced the world.

In a new book on Soleri, Italian architect Renzo Piano, winner of the Pritzker Prize, architecture's highest honor, wrote: "For me and all the other architects from my generation, he has been a great push, utopian and realistic at the same time. . . . Only now we finally understand how fragile Earth is. He figured it out 50 years ago. All our work takes inspiration from those early intuitions."

Will Bruder is a former apprentice under Soleri. In his career he designed, among other things, the Burton Barr Central Library in Phoenix.

For him, there is no denying Soleri's impact.

"He was behind the idea of the city and nature living in harmony," Bruder said. "He is more widely known abroad than he is here, especially in Asia and Europe."

Bruder says that much of the work of modernist architects is "derivative" of Soleri.

"I could show you Paolo's sketches and sketches drawn in the past five years, and you would be hard-pressed to tell me which came first."

Bruder knows, however, that Arcosanti never became what Soleri dreamed.

"It's bittersweet," Bruder said. "You wish there could have been the right chemistry to get the right funding to get more done."

. . .

Soleri jokes about his age. At 91, he says he is losing his hearing, his vision and his mind. But he is not. His age has been a blessing if only because it has given him more time to work. "I am lucky, yes. But boy oh boy."

Soleri still works nearly every day, drawing new plans or writing new opinions. He routinely paints nudes. The drawings are also sold in the bookstore. Most of his time is now spent at Cosanti, his original studio and residence in Paradise Valley.

Forty years into Arcosanti, he says the fact that so little has been built does not bother him. And in fairness, he said from the beginning that it would take generations for people to change.

"I never thought there would be an immediacy," he says. "I am asking too much. People are who they are. It takes time. Generations or more."

. . .

In the ravine underneath Arcosanti, there is a cluster of 20 or so 9-by-9-foot structures. Residents call them the cubes.

The cubes are where Soleri and his fellow dreamers stayed when they first arrived in 1970. Back then, and still today, Soleri called the vision "arcology," a word he invented combining architecture and ecology.

That same year, an exhibition of his drawings and plans, called "The Architecture Vision of Paolo Soleri," was touring the country stopping at museums.

It was an exciting time. "Oh yes," Soleri said. "But we were naive."

Forty years later, the view from the cubes remains impressive, especially at night.

Arcosanti looks bigger than it really is. The voices of its residents echo across the canyon.

To the south, however, is another sight. A jaundiced glow of light rises from Phoenix and its suburbs.

When Soleri was building his first cubes, the population of metropolitan Phoenix was less than 1 million.

Today, it is 4.2 million, a rambling splatter of freeways and driveways. Jobs are miles away from homes. Air-conditioning units rumble, artificially cooling a place that lives much the way the rest of suburban America lives.

While Soleri was dreaming, the vision he abhorred became reality.

But over the past 40 years, slowly, something else began to happen.

The world began to talk about low-impact building, solar heating, preserving open spaces.

Builders began to create mixed-use developments that keep people from having to drive everywhere, that try to create a sense of belonging.

Arcosanti, sitting at the end of that long dirt road, remains more dream than reality. But the ideas born there are no longer on the fringes.